L. P., aged thirty-one, single, a printer by trade, applied to me, January, 1863, suffering from what I at first decidedly thought was cervico-brachial neuralgia, the pain having followed exposure to cold and wet, situated in the lower part of the neck, the shoulder, elbow and inner side of the right arm, and existing nowhere else. The character of the pain was described as at least remittent, if not distinctly intermittent. The pulse was not more than 78; the tongue was thickly coated with white fur, but the man did not complain of thirst, and there were no evident signs of fever. As the pains had only existed for about a fortnight, it appeared an excellent case for cure by the hypodermic injection of morphia; and, accordingly this was used in quarter-grain doses twice a day. After about ten days an attempt was made to do without the morphia, but the pains returned, worse than before, and meantime the tongue had remained uniformly coated, and was now very yellow; the appetite was bad, and there was some increase in frequency of pulse. It now struck me, for the first time, that the man presented, in a slight degree, the sallow and red tint and oily features of a rheumatic patient; it was now found that sweat and urine were distinctly acid. Acting on this idea, I administered five grains of iodide of potassium, and thirty grains of bicarbonate of potassium, four times every twenty-four hours, after giving a moderate saline aperient. The result was manifest improvement within twenty-four hours, and almost complete relief of the pain within three or four days (the urine never becoming distinctly alkaline, however.) As the attack subsided, the oily appearance of the skin disappeared, and the rheumatic tint was replaced by mere ordinary pallor, which the patient lost after taking a short course of steel. At the time this case occurred to me, I was not aware of the importance, in doubtful instances, of looking to the temperature; but subsequent experience has convinced me that in every truly rheumatic case, however limited in extent, there is a real, though it may be a small, rise of temperature. The thermometer will be found to mark from 99-1/4° to 100° Fahr., and this, joined with the appearances above mentioned, and a strong acidity of urine, will be sufficient to distinguish the complaint as rheumatic; and the striking effect of such remedies as iodide with bicarbonate of potash, followed up with sesquichloride of iron, in full doses, helps still further to distinguish the cases from true neuralgias. Since the introduction of the full doses of the iron-tincture in the treatment of acute rheumatism, I have had the opportunity of treating two of these cases of subacute rheumatism in the same manner, viz., with the iron from the first, and the results have been most satisfactory in every way. These cases were independent of a much larger number, treated in the same way, in which the symptoms of rheumatism were more generalized and more severe.